226
8.3.3
Execute Transfer Count Register (ETCR)
ETCR is a 16-bit readable/writable register that specifies the number of transfers. The function of
this register is different in normal mode and in block transfer mode.
ETCR is not initialized by a reset or in standby mode.
(1) Normal Mode
ETCRA
Transfer Counter
Bit
:
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ETCR
:
Initial value :
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
R/W
: R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W
*
: Undefined
In normal mode, ETCRA functions as a 16-bit transfer counter. ETCRA is decremented by 1 each
time a transfer is performed, and transfer ends when the count reaches H'0000. ETCRB is not used
at this time.
ETCRB
ETCRB is not used in normal mode.
(2) Block Transfer Mode
ETCRA
Holds block size
Bit
:
15
14
13
12
11
10
9
8
ETCRAH
:
Initial value :
*
*
*
*
*
*
*
*
R/W
:
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Block size counter
Bit
:
7
6
5
4
3
2
1
0
ETCRAL
:
Initial value :
*
*
*
*
*
*
*
*
R/W
:
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
*
: Undefined
Содержание H8S/2631
Страница 28: ...xviii Appendix G Package Dimensions 1154 ...
Страница 341: ...316 Transfer SAR or DAR DAR or SAR Block area First block Nth block Figure 9 8 Memory Mapping in Block Transfer Mode ...
Страница 918: ...905 ø DREQ0 DREQ1 tDRQS tDRQH Figure 25 19 DMAC DREQ Input Timing ...
Страница 955: ...943 A 2 Instruction Codes Table A 2 shows the instruction codes ...